Question

1. We wached a film I Lii e сделать отрицательное​

Answer 1

Если предложение изначально We watched a film, то отрицательным оно будет: We didn't watch a film

Answer 2

It seems like you want to turn the sentence "We watched a film" into a negative statement. To do that, you can simply add the word "not" to create a negative sentence. Here's the revised sentence:

"We did not watch a film."

In this sentence, "did not" is used to form the negative past tense.